Groundbreaking Experiment Online with Help from Cal Poly Students

Aaron Wong cleans specialized equipment inside of the Laboratori Nazionali de Gran Sasso in Italy. The equipment is used in the Cryogenic Underground Observatory for Rare Events collaboration.
Contributed Photo: Laura Marini
 

Why is the universe full of matter instead of antimatter? An experiment more than a decade in the making is now starting to answer that question, and Cal Poly students contributed to getting it up and running.

Every summer, a few Cal Poly students advised by physics Professor Tom Gutierrez have traveled to Italy’s Gran Sasso National Laboratories to help construct CUORE or to work on the prototypes that preceded it.

The CUORE collaboration is searching for an event so rare no one has ever seen it happen. The event — called neutrinoless double-beta decay — would help to explain why the universe is full of matter instead of antimatter. If the decay happens, it would change the current laws of physics.

The experiment consists of an array of about 1,000 tellerium dioxide crystals cooled down almost to absolute zero and fitted with extremely sensitive devices that measure temperature. If a specific rise in temperature occurs, it would indicate that neutrinoless double-beta decay had taken place. If the temperature doesn’t rise, scientists can say with certainty that the decay won’t happen in a given period of time.

The experiment is now online and providing data.

“The results so far indicate that neutrinoless double-beta decay is outrageously rare,” Gutierrez said, once every thousand trillion universes, to be exact. Though that seems like an impossibly long time, some models of how the universe works predict that the decay would happen even less frequently than that.

“You learn a lot about the universe by putting limits on it, and you learn a lot by building a detector that’s this sensitive,” said Gutierrez.

CUORE may also be able to detect dark matter. This iteration of the experiment will run for five years.